Field-Point Pressures in the Vicinity of a Series of Skewed Marine Propellers
Abstract
Total fluctuating pressures were measured on a flat plate adjacent to a model propeller operating in the 24-inch water tunnel. The effects of blade skew on propeller-induced field pressures are shown. The amplitude and phase of the blade-rate portions of the measured induced pressures are compared with the Kerwin prediction of propeller field-point pressures for operation in uniform flow at the design advance coefficient and for two propeller tip clearances. Experimental results and theoretical predictions for total field-point pressures were in good agreement for both amplitude and phase. In addition to the measurements made in uniform flow, induced pressures were also measured for the propellers operating in nonuniform flows generated by 4- and 5-cycle wake screens placed upstream of the propeller. Experimental results of tests in uniform and nonuniform flow at the same mean thrust coefficient showed that increasing blade skew had the effect of reducing propeller-induced pressures and that increasing blade skew displaced the peak amplitude signal farther downstream.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1970
- Accession Number
- AD0873599
Entities
People
- Stephen B. Denny
- Stephen S. Teel